The present invention relates to a wheel for motor vehicles including a wheel hub, a rim, and spokes by which the wheel hub and the rim are connected with one another.
A wheel for motor vehicles, in which a wheel hub is connected with a rim by spokes which have Y-shaped cross-sections, is known from German Patent Document DE 18 02 298 A1. Standing flanges of the spokes are arranged on the forward side of the wheel end on a disk-shaped surface of the wheel hub. Fork-shaped sections of the webs provided on the rearward side of the wheel are connected to a ring body of the wheel hub. The openings formed between the spokes are partially closed by a disk element in the areas adjoining the wheel hub. The wheel hub is provided with indentations which are open toward the rearward side of the wheel and which are arranged between fastening openings for wheel bolts. On both its inner circumference and its outer circumference, the wheel hub is bounded by a continuous, approximately cylindrically shaped area.
It is an object of this invention to provide a wheel for motor vehicles which has both low weight and high stability.
According to the invention, this object is achieved by providing the spokes of a wheel, in first areas connected with the wheel hub, with solid cross-sections and, in second areas connected with the rim, with V-shaped cross-sections. The spokes are arranged such that the transitions between the first and second areas are progressive; that is, along the longitudinal course of a spoke from the wheel hub toward the rim, the cross-section changes from an initially solid cross-section, which preferably has an elliptical construction, to a triangular solid cross-section, which then changes further to a V-shaped cross-section while forming a central groove. As a result of this construction, a solidly constructed area is provided at the location of the highest loading of the spoke, specifically at the transition to the wheel hub. The solidly constructed area has high stability. The V-shaped spoke cross-sectional configuration arranged in the area of the rim takes advantage of reduced loading by saving material. Simultaneously, the V-shaped construction provides a high rigidity in the transverse direction of the wheel. High rigidity in this transverse direction is important, particularly during cornering, because, in this condition, lateral forces are introduced to the wheel along a smaller circumferential area.
Advantageous further developments of the invention are reflected in certain claims.
The spokes can be arranged so that they correspond with openings for receiving fastening bolts in the wheel hub. In this case, the fastening bolts and, therefore, the wheel hub accommodate one-sided introduction of force as lengthening of the spokes, so that a centric introduction of force into the spokes takes place. Together with the first areas of the spokes adjoining the wheel hub, third areas are formed which comprise the fastening bolts and which result in good distribution and introduction of force into the spokes.
The wheel hub is preferably constructed to have indentations between the openings for the fastening bolts. The indentations are open toward the interior side of the wheel. One continuous, approximately cylindrically constructed body, respectively, is provided on each of the inner and outer circumferences of the wheel hub. On its exterior side, the wheel hub is closed off by a surface which is perforated by the openings for the fastening bolts. To the extent that it is necessary, a continuous opening for receiving an axle journal can naturally be provided in the center of the wheel hub. A shell-shaped wheel hub which is highly stable and which has a low weight is therefore formed.
In the second areas, the spokes may be constructed with V-shaped cross-sections such that, on each of the legs forming a “V”, free faces are provided with thickenings extending in the longitudinal directions of the spokes. As a result of these thickenings, the susceptibility of the faces, and also of the legs, to damage is reduced. Simultaneously, the thickenings contribute to a further increase in the stability of the spokes in the second areas.
Finally, the legs forming the V-shaped cross-sections may be constructed in the second areas such that, in each spoke, their widths increase continuously over the course of the spoke toward a linkage to the rim. Simultaneously, spreading of the legs can be increased along the course of the spoke in the direction of the rim, or the legs can be provided with curvatures defining spreading. This configuration in the area by which the spoke is linked to the rim improves the introduction of peripheral forces from the spoke into the rim. In this context, the wall thickness of the legs can be decreased as the width of the legs increases. If a thickening is provided on faces of the legs, the thickening should decrease to a smaller degree than the wall thickness of the legs.